1. Field of the Invention
The present invention relates to an image processing device and method.
2. Description of the Prior Art
Stereoscopic imaging in which a stereo pair of images may be viewed together so as to give an appearance of a three dimensional image has been popular for over a century. To create an illusion that an image is three-dimensional (3D), two slightly different images may be viewed together so that one of the images is viewed by a user's left eye and the other image is viewed by a user's right eye. Provided that the two images correspond to two slightly different views of the same scene (for example each image in the pair being as if seen from the user's left eye and right eye respectively), the user's brain will fool the user into thinking that the pair of images is one three dimensional image when the images are viewed in a suitable manner. An object within the images will appear at an apparent depth from the display which is dependent upon an offset amount between the left-hand image corresponding to that object and the right-hand image corresponding to that object.
In order to try and ensure that each eye sees the image that is intended to be viewed by that eye, many techniques are known. In some techniques, each image of the stereo pair can be reproduced in such a way so as to be separable from the other image. For example, the left-hand image could be displayed next to the right-hand image and a suitable viewer such as a stereoscope used to view the images. This method of displaying the images was used in the earliest forms of 3D images.
Alternatively, a left-hand image intended to be viewed by the left eye may be polarised in the vertical direction, whilst a right-hand image intended to be viewed by the right eye may be polarised in the horizontal direction. The left-hand image and right-hand image are then superimposed on each other. By wearing appropriate glasses in which a polarisation of each lens corresponds with the desired image to be viewed, the correct image for each eye will be viewed by the user. Many other systems of displaying and viewing the images are also known such as circular polarisation, coloured filters (e.g. red/cyan anaglyph), chromadepth, and anachrome; these systems require a user to wear an appropriate pair of glasses. In other systems, such as displays which use a lenticular display system, it is not necessary for a user to wear any glasses in order to view a three-dimensional image.
Several techniques for generating a stereo pair of images are known. A common system for producing a pair of images for viewing together as a stereo pair of images comprises two cameras offset from each other so as to capture two different images of the scene. One camera is used to capture the left-hand image, and the other camera is used to capture the right-hand image. The two captured images can then be viewed together as a 3D image using one of the techniques described above.
Recently, with the advent of high definition video cameras and television broadcasts, some broadcasters have used a pair of high definition video cameras to capture high definition images of sports events such as football matches and boxing matches for reproduction as 3D images. However, current high definition video camera arrays for capturing 3D images are very expensive. Furthermore, mismatches in image luminance and chrominance between the two cameras can cause eye discomfort and headaches for a user as the brain will try and make the two images appear to be the same.
Techniques for generating 3D images from two-dimensional (2D) images are also known. For example, the 2D image may be considered to be the left-hand image for viewing by the left eye. To generate the right-hand image, an operator may select an object within a scene, decide at what depth that object should appear in the scene, and apply an image offset amount for that object within that scene so as to generate the right-hand image. An example of such a process is termed Dimensionalization® which is implemented by In-Three Inc. However, in order to recreate realistically a 3D image from a 2D image, an operator may have to use their artistic judgement regarding the depth of objects within the scene. Furthermore, each frame of video footage or movie still must be marked up individually by the operator so as to define the objects and their respective depths within the image. As well as being expensive, this process can be very time consuming and labour intensive, thus meaning that it is likely to be impossible to create 3D video in real-time from video images captured by a single camera.
The present invention seeks to alleviate or mitigate the above problems.